Examples of surface inspection systems for various web materials such as aluminum or plastic sheets of indeterminate length, which photoelectrically scan the surface of the material with a flying spot of light, are disclosed in U.S. Pat. Nos. 3,589,817 and 2,904,174. When applying such an inspection system to a web drive so as to inspect a surface of a web material which is continuously driven, an inspection beam scans the web surface and the light either reflected from or passed through the web surface is collected to evaluate the quality of the web surface. If a surface defect is detected, a marker is actuated so as to mark that part of the web material that contains the surface defect. The web material is stopped when the marked part of the web material reaches a specified position where a visual inspection is to be made for deciding whether the surface defect is acceptable